Printing devices such as inkjet printers, laser printers, copiers, and facsimile machines often house stacks of paper or other media used in the printing process. The stacks of paper are usually in one or more trays that are incorporated into the printing device. Printing devices often have an automatic feeding mechanism to pull sheets of print media from the tray into the printing apparatus, where text, graphics, or other images may be printed on the sheets.
Sometimes, the automatic feeding mechanism may pull multiple sheets from the supply of print medium at one time. This often jams the printing device or causes other problems. To prevent the introduction of multiple pages into the transport path of the printing device at the same time, most printing devices include a separation pad. Separation pads are usually a small flap of rubber located adjacent to a main feed roller. As the name suggests, a separation pad is intended to separate sheets of print media as they enter the transport path of a printing device. Separation pads are generally biased toward the main feed roller and, over time, they become worn or contaminated and require replacement.
When a worn or contaminated separation pad is not replaced in a timely manner, multiple sheets are more likely to be feed into the printing device by the feeding mechanism. As noted, introducing multiple pages into a printing system usually result in jams. Simultaneously feeding multiple sheets can also cause poor printing quality and, sometimes, damage to printing system components. Therefore, the correct operation of separation pads is often important to the printing process.
While separation pads often work properly for the printing of many hundreds or even thousands of pages, when they do wear out or become contaminated, they are presently very difficult to replace. The difficulty with replacing separation pads on existing printing devices is so extreme that most manufacturers suggest that the ordinary user not attempt to make a replacement. Rather, most manufacturers suggest that ordinary users take their printing devices to an authorized printing system service dealer for separation pad replacements. In fact, in most vertical feed printing devices the replacement of a separation pad requires the almost complete disassembly of the printing device. In printing devices with a C-type paper path, the separation pad must be removed from a very narrow slot where the print media enters the printing device, which also usually requires some disassembly. Disassembly of current printing devices to replace the separation pad requires the use of tools and/or special equipment that many ordinary users do not have.
Because current printing systems require at least some disassembly of the printing device, attempts to replace separation pads often results in damage to the main feed roller assembly or other printer components, especially when an ordinary consumer or other person relatively unfamiliar with printing device attempts the replacement. However, taking a printing device to an authorized service dealer is usually quite inconvenient for the user because of the time spent without the printing device. In addition, it is often expensive to ask an authorized service representative to make the replacement.
There are some printing devices that use an opposing roller instead of a separation pad. However, such rollers are relatively uncommon in low cost printing devices, i.e., under $500.